1. The Field of the Invention
The instant invention provides methods relating to medical and diagnostic technology. In particular, the present invention provides substantially non-invasive methods for collecting cells from the internal organs of a subject.
2. The Background Art
The diagnosis of many diseases requires an analysis of cells collected from specific internal organs, such as the lungs, kidneys, uterus, or bladder. Often, invasive procedures such as punch biopsies, needle biopsies, cystoscopy, scrapings, and the removal of portions of the internal organ are required to collect the quantities and types of cells necessary for analysis. Such methods are expensive and often cause considerable subject discomfort leading to decreased subject compliance and limiting mass screening for certain disease states, especially cancer.
Bladder carcinoma illustrates the need for a less expensive, more efficient, and substantially non-invasive method for collecting cells for disease analysis. This cancer is associated with cigarette smoking and certain chemical industry occupations and is one of the most prevalent forms of cancer in the general population. Furthermore, about half of those treated for bladder cancer will suffer a recurrence of the disease within five years of treatment. Thus, monitoring asymptomatic patients for recurrence of bladder lesions is particularly important. Providing efficient and inexpensive methods for the early detection and diagnosis of this disease could therefore provide significant public benefits.
Unfortunately, since the bladder cannot be examined by external viewing diagnosis of cancer or other ailments frequently does not occur until macroscopic hematuria (blood in the urine) or another observable symptom occurs. Methods such as cystoscopy and contrast urography are widely used for monitoring and diagnosing bladder cancer. However, cystoscopy involves an invasive examination of the bladder, is expensive to perform, and causes significant patient discomfort. Urine cytology, wherein cells collected from urine are examined for morphologic changes indicative of a disease state, is a non-invasive procedure but possesses insufficient sensitivity and accuracy for routine use.
Thus, it would be advantageous to have a more efficient, less invasive method for collecting cells from the internal organs of a subject. Such a method would reduce the cost of, and facilitate subject compliance with, detecting diseases in which cells from an internal organ are collected for performing diagnosis. Furthermore, such a method would facilitate the detection of disease states before macroscopic evidence of disease state became present and would facilitate inexpensive mass screening for diseases.